AP3B2

Protein identityUniProt · HPA

UniProt accession

Q13367

Gene

AP3B2

Ensembl

ENSG00000103723

Chromosome

15

Canonical length

1082 aa

Protein class

Disease related genes, Human disease related genes, Predicted intracellular proteins

Subcellular location

Nucleoplasm,Golgi apparatus,Cytosol

OverviewNCBI Gene

Adaptor protein complex 3 (AP-3 complex) is a heterotrimeric protein complex involved in the formation of clathrin-coated synaptic vesicles. The protein encoded by this gene represents the beta subunit of the neuron-specific AP-3 complex and was first identified as the target antigen in human paraneoplastic neurologic disorders. The encoded subunit binds clathrin and is phosphorylated by a casein kinase-like protein, which mediates synaptic vesicle coat assembly. Defects in this gene are a cause of early-onset epileptic encephalopathy. [provided by RefSeq, Feb 2017]

Canonical amino-acid sequenceUniProt

1082 residues, UniProt reviewed canonical sequence.

>Q13367|AP3B2
     1  MSAAPAYSED KGGSAGPGEP EYGHDPASGG IFSSDYKRHD DLKEMLDTNK DSLKLEAMKR
    61  IVAMIARGKN ASDLFPAVVK NVACKNIEVK KLVYVYLVRY AEEQQDLALL SISTFQRGLK
   121  DPNQLIRASA LRVLSSIRVP IIVPIMMLAI KEAASDMSPY VRKTAAHAIP KLYSLDSDQK
   181  DQLIEVIEKL LADKTTLVAG SVVMAFEEVC PERIDLIHKN YRKLCNLLID VEEWGQVVII
   241  SMLTRYARTQ FLSPTQNESL LEENAEKAFY GSEEDEAKGA GSEETAAAAA PSRKPYVMDP
   301  DHRLLLRNTK PLLQSRSAAV VMAVAQLYFH LAPKAEVGVI AKALVRLLRS HSEVQYVVLQ
   361  NVATMSIKRR GMFEPYLKSF YIRSTDPTQI KILKLEVLTN LANETNIPTV LREFQTYIRS
   421  MDKDFVAATI QAIGRCATNI GRVRDTCLNG LVQLLSNRDE LVVAESVVVI KKLLQMQPAQ
   481  HGEIIKHLAK LTDNIQVPMA RASILWLIGE YCEHVPRIAP DVLRKMAKSF TAEEDIVKLQ
   541  VINLAAKLYL TNSKQTKLLT QYVLSLAKYD QNYDIRDRAR FTRQLIVPSE QGGALSRHAK
   601  KLFLAPKPAP VLESSFKDRD HFQLGSLSHL LNAKATGYQE LPDWPEEAPD PSVRNVEVPE
   661  WTKCSNREKR KEKEKPFYSD SEGESGPTES ADSDPESESE SDSKSSSESG SGESSSESDN
   721  EDQDEDEEKG RGSESEQSEE DGKRKTKKKV PERKGEASSS DEGSDSSSSS SESEMTSESE
   781  EEQLEPASWS RKTPPSSKSA PATKEISLLD LEDFTPPSVQ PVSPPAIVST SLAADLEGLT
   841  LTDSTLVPSL LSPVSGVGRQ ELLHRVAGEG LAVDYTFSRQ PFSGDPHMVS VHIHFSNSSD
   901  TPIKGLHVGT PKLPAGISIQ EFPEIESLAP GESATAVMGI NFCDSTQAAN FQLCTQTRQF
   961  YVSIQPPVGE LMAPVFMSEN EFKKEQGKLM GMNEITEKLM LPDTCRSDHI VVQKVTATAN
  1021  LGRVPCGTSD EYRFAGRTLT GGSLVLLTLD ARPAGAAQLT VNSEKMVIGT MLVKDVIQAL
  1081  TQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against AP3B2 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability

Intracellular

Secreted

No

Transmembrane segments

0

Mean surface accessibility (rSASA)

0.36

Highest tissue expression

46 nTPM

Expression across tissuesHPA

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about AP3B2.

Disease | AllUniProt

Conditions AP3B2 is implicated in, by any mechanism.

• Developmental and epileptic encephalopathy 48 (DEE48) MIM:617276

Disease | GeneticClinVar

51 pathogenic / likely-pathogenic of 941 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

• Developmental and epileptic encephalopathy, 48
• Epileptic encephalopathy

ReferencesPubMed · IEDB

Publications for AP3B2 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)

0.34

gnomAD pLI

0.77

gnomAD missense Z

2.92

DepMap mean gene effect

-0.02

DepMap dependency class

selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

• anterograde axonal transport
• anterograde synaptic vesicle transport
• clathrin-coated vesicle cargo loading, AP-3-mediated
• intracellular protein transport
• synaptic vesicle coating
• synaptic vesicle recycling
• vesicle-mediated transport

Cellular components

• AP-3 adaptor complex
• axon cytoplasm
• clathrin-coated vesicle membrane
• early endosome
• Golgi apparatus
• intracellular vesicle
• presynapse

Protein domainsUniProt · Pfam · InterPro

• Clathrin/coatomer adaptor, adaptin-like, N-terminal
• Armadillo-like helical
• Clathrin adaptor, appendage, Ig-like subdomain superfamily
• Armadillo-type fold
• AP complex subunit beta
• AP-3 complex subunit beta
• AP-3 complex subunit beta, C-terminal domain
• AP-3 complex subunit beta-1/2, C-terminal domain
• Adaptin N terminal region
• Clathrin-adaptor complex-3 beta-1 subunit C-terminal
• AP-3 complex subunit beta-1, C-terminal domain

KeywordsUniProt

• Cytoplasmic vesicle
• Epilepsy
• Golgi apparatus
• Membrane
• Phosphoprotein
• Protein transport
• Transport

InteractionsUniProt · HPA

Protein binding partners of AP3B2 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

• ATM
• DTNBP1